I just wanted to report back that I have solved this now and thank everyone
for their help.
What I kept running into, which floored me was that with rexx\sql you have
to run the loadfuncs function, when you start on a new thread, even though
rxFuncQuery reports the functions as already loaded.
Once I got that into my head, I could load/unload the functions on each
invocation of the server and the server could shut itself down (after a
suitable quiescent interval - thanks for that hint Rony - saves a great deal
of thrashing)
Jon
On 2 April 2011 19:55, Sahananda (Jon) Wolfers <[email protected]>wrote:
> Hi Bill,
>
> this is the conclusion I had come to when I read Mark last. I won't start
> the server in the init class method, but anything that uses it will have to
> start it and then stop it when they have finished. Starting when already
> started will just add to the usage count. Stopping decreases it and when it
> is 0 it really stops. It will mean changing my existing code a bit (which I
> had hoped to avoid), but it seems the sensible way to go.
>
> thanks,
>
> Jon
>
> PS: thanks Rony - that gave me something to think about.
>
>
>
>
> On 2 April 2011 19:13, Bill Turner, WB4ALM <[email protected]> wrote:
>
>> Jon, Can you also implement a global "usage count"? When the count is
>> zero, the service can shutdown.
>>
>> That way both A and B increment the count by one when they start, and
>> reduce it by one when they terminate when they quit.
>>
>> if somebody else starts then count goes up one more. Eventually everybody
>> will quit and the count becomes zero.
>> when it is zero the server shuts its self down.
>>
>> Using your example, the count could get to four
>>
>> a script called C calls A (count +1) which calls B (count +1) [count is
>> now 2]
>> another script D calls B (count +1) then calls A (count +1) [count is
>> now 4]
>>
>> As CAB processes and each called routine terminates, the count becomes
>> three and two...
>> As DBA processes and each called routine terminates, the count becomes one
>> and zero...
>>
>> This also allows for intertwining... and when the count is zero, the
>> server could either decide to terminate
>> or go into a "sleep" before terminating. Maybe a count of "-1" means that
>> we are getting ready to shutdown,
>> so that other routines know to wait before trying to start the server back
>> up...
>>
>> /s/ Bill Turner, wb4alm
>>
>>
>>
>>
>>
>> On 04/02/2011 11:28 AM, Sahananda (Jon) Wolfers wrote:
>>
>> Hi Mark & Gil,
>>
>> thank you both for your help, but I think what it points to is I have not
>> explained myself.
>>
>> Both of those aproaches predicate a single client using the server. Let's
>> say I have two routines called A & B that both use the server and have
>> reqires directives in their scripts.
>>
>> a script called C calls A which calls B
>> another script D calls B then calls A
>>
>> Whichever way around they are run, the first one 'require'ed will start up
>> the server.
>> If one of them shuts it down when it terminates, then it is not available
>> to the other.
>>
>> My problem is not shutting it down, but rather knowing when it is
>> apropriate to shut it down.
>>
>> I'm sorry that I'm still worrying away at this on the lists after a year
>>
>> Jon
>>
>> On 2 April 2011 16:06, Mark Miesfeld <[email protected]> wrote:
>>
>>> On Sat, Apr 2, 2011 at 7:03 AM, Sahananda (Jon) Wolfers <
>>> [email protected]> wrote:
>>>
>>>> I have a question, and I hope it is ok to ask it here.
>>>>
>>>> It has been brought up by my struggle to move my work to 4.0, but if
>>>> solved for me could benefit many people.
>>>>
>>>>
>>>>
>>>> My specific problem is about managing to use rexx/sql with ooRexx 4.0 in
>>>> a multithreaded environment, but it might b better if I ask the list a more
>>>> general question.
>>>>
>>>>
>>>>
>>>> That is, where one has to provide one’s applications with a service that
>>>> continuously runs, what is the best way to set it up, use it and tear it
>>>> down. This question has become more important in 4.0, because there
>>>> used to be a loophole in ooDialog that allowed one to run methods on the
>>>> ‘main’ thread of a dialog. Now that has gone, it needs to be done
>>>> properly.
>>>>
>>>>
>>>>
>>>> So for me, because rexx\sql needs to run on the thread that the library
>>>> was loaded on, I have built a little server, I queue message objects on the
>>>> server, and it performs them on the correct thread. That all works
>>>> very well. My problem pertains to how to set it up when it is first
>>>> needed, and tear it down when it is finished with.
>>>>
>>>
>>> Well, as always questions like this are hard to answer without knowing
>>> what your code is doing.
>>>
>>> But, one approach comes directly from what you say above. If you are
>>> queueing messages to the server, just define a special message that means
>>> "shut down". Then when your application is terminating, send it that
>>> message.
>>>
>>> I doubt that there is any one "right" way to do this.
>>>
>>> Another approach is to have some variable that the server checks each
>>> time it enters its processing loop. If the variable is true, it drops out
>>> of the loop and the thread terminates. Then when the application is
>>> terminating you set the varible and manually force the server to check if it
>>> needs to process something.
>>>
>>> Again, I'd suggest looking at the sysinfo.rex example in trunk. It
>>> solves a problem that seems to be similar to yours, every use of OLE has to
>>> be done on the same thread.
>>>
>>> main\samples\windows\oodialog\sysinfo
>>>
>>> --
>>> Mark Miesfeld
>>>
>>>
>>>
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